Undefined reference to glewinit, glfwExperimental and many more

Question

I am very new to c++ and I am trying to use opengl with glfw. I am using ubuntu 18 on wsl. I have GL and GLFW on my include directory and I have included it in my code.

#include <stdio.h>
#include <stdlib.h>
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <glm/glm.hpp>
using namespace glm;

int main(){
    glfwWindowHint(GLFW_SAMPLES, 4); // 4x antialiasing
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3); // We want OpenGL 3.3
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // To make MacOS happy; should not be needed
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); // We don't want the old OpenGL 


    GLFWwindow* window; // (In the accompanying source code, this variable is global for simplicity)
    window = glfwCreateWindow( 1024, 768, "Tutorial 01", NULL, NULL);
    if( window == NULL ){
        fprintf( stderr, "Hi\n" );
        glfwTerminate();
        return -1;
    }
    glfwMakeContextCurrent(window); // Initialize GLEW
    glewExperimental=true; // Needed in core profile
    if (glewInit() != GLEW_OK) {
        fprintf(stderr, "Failed to initialize GLEW\n");
        return -1;
    }
}

I am using g++ to compile the program. When I use g++ -c main.cpp it compiles but throws a binary error when I try to run the program and when I use g++ main.cpp -IGL -IGLFW -Iglm I get that error. Am I missing something?

Error:

/usr/bin/ld: /tmp/cco9YYTw.o: in function `main':
main.cpp:(.text+0x17): undefined reference to `glfwWindowHint'
/usr/bin/ld: main.cpp:(.text+0x26): undefined reference to `glfwWindowHint'
/usr/bin/ld: main.cpp:(.text+0x35): undefined reference to `glfwWindowHint'
/usr/bin/ld: main.cpp:(.text+0x44): undefined reference to `glfwWindowHint'
/usr/bin/ld: main.cpp:(.text+0x53): undefined reference to `glfwWindowHint'
/usr/bin/ld: main.cpp:(.text+0x74): undefined reference to `glfwCreateWindow'
/usr/bin/ld: main.cpp:(.text+0xa4): undefined reference to `glfwTerminate'
/usr/bin/ld: main.cpp:(.text+0xb7): undefined reference to `glfwMakeContextCurrent'
/usr/bin/ld: main.cpp:(.text+0xbd): undefined reference to `glewExperimental'
/usr/bin/ld: main.cpp:(.text+0xc3): undefined reference to `glewInit'
collect2: error: ld returned 1 exit status

Answer 1

To build your example you should install the following dependencies on your Ubuntu with apt-get

• libglm-dev, libglfw-dev, libglew-dev, cmake

I've used CMake to build your file

Put the following CMakeLists.txt file in your folder where .cpp file located (I copied your code into a file named glfw_sample.cpp)

cmake_minimum_required(VERSION 3.10)

project(glfw_sample)

find_package(GLEW REQUIRED)
find_package(PkgConfig REQUIRED)
pkg_search_module(GLFW REQUIRED glfw3)

add_executable(${PROJECT_NAME} glfw_sample.cpp)
target_include_directories(${PROJECT_NAME} PRIVATE ${GLFW_INCLUDE_DIRS})
target_link_libraries(${PROJECT_NAME} PRIVATE GLEW::GLEW ${GLFW_LIBRARIES})

Then execute in a shell

cmake -S. -Bbuild
cmake --build build

If no errors occurred on both steps you'll find glfw_sample executable in the build folder.

I use the following links to build your code:

1. https://www.glfw.org/docs/3.0/build.html
2. https://cmake.org/cmake/help/latest/module/FindGLEW.html

Answer 2

A very quick google search might help: glfw-errors-with-glfwwindowhint

Link to -lglfw3 not -lglfw - if this is correct, please vote up the linked-to-answer and not this one

To cover the location of the library, from compile-glfw-on-ubuntu-and-fix-libglfw-so-cannot-open-error

This is because the GLFW installer puts libglfw.so in /usr/local/lib instead of /usr/lib like Ubuntu expects. But /usr/local/lib is a fine place to put shared libraries for most of the Unix world, so let’s just tell Ubuntu to look there when linking our program. You’ll want to edit /etc/ld.so.conf and add the line “/usr/local/lib” to the file, then save. Afterwards you should run ldconfig as root. Something like this:

sudo vim /etc/ld.so.conf
# Add the path and save - then try to build again